橡楚编辑部 9/7/2026 46 min read
This article comprehensively analyzes the core performance advantages of LSR silicone rubber, including excellent high and low temperature resistance, biocompatibility, insulation and aging resistance. It sorts out its typical application scenarios in medical, automotive, consumer electronics, maternal and infant products and other fields, and explains the key process points of liquid injection molding, providing practical references for practitioners in material selection and processing applications.
Liquid silicone rubber (LSR, LSR硅橡胶) is a two-part, high-purity addition-cure elastomer that has emerged as a material of choice for high-performance applications across medical, automotive, consumer electronics, and industrial sectors. Unlike traditional heat-cure rubber (HCR) and room-temperature vulcanize (RTV) silicones, LSR is processed via liquid injection molding (LIM), enabling high-volume, precision manufacturing of complex geometries with tight tolerances. Its unique combination of thermal stability, biocompatibility, mechanical resilience, and dielectric strength addresses unmet needs that conventional thermoplastics and organic rubbers cannot fulfill. This analysis systematically explores the core material properties of LSR硅橡胶, advanced processing methodologies, cross-industry applications, and emerging innovation trends, providing a technical reference for material selection and product development teams.
LSR硅橡胶’s performance is derived from its unique molecular structure, consisting of a polydimethylsiloxane (PDMS) backbone with alternating silicon-oxygen (Si-O) bonds, supplemented with reinforcing fillers and functional additives. This section breaks down its key mechanical, thermal, chemical, and biological properties, with comparative data to contextualize its performance against competing materials.
LSR exhibits a balanced set of mechanical properties that remain consistent across a wide temperature range, making it suitable for applications exposed to extreme environmental conditions. Key mechanical and thermal parameters are summarized in Table 1, with comparisons to common engineering materials to highlight LSR’s competitive advantages.
Notably, LSR retains >80% of its room-temperature tensile strength when exposed to 200°C for 1,000 hours, while NBR loses 60% of its tensile strength under identical conditions. Its extremely low Tg ensures flexibility even in cryogenic environments, a critical feature for aerospace and cold-chain logistics applications. For high-temperature scenarios, specialty LSR grades doped with iron oxide or cerium additives can extend continuous service temperatures to 300°C, with short-term exposure resistance up to 350°C.
LSR also exhibits exceptional dynamic performance: it has a compression set of <10% after 70 hours at 175°C (per ASTM D395 Method B), outperforming NBR’s 30–40% compression set under the same test conditions. This makes LSR ideal for sealing and gasket applications that require long-term dimensional stability under repeated load cycles.
LSR硅橡胶’s Si-O backbone is inherently more resistant to oxidative degradation, UV radiation, and chemical exposure than carbon-backbone organic rubbers. Its chemical resistance profile is categorized below:
For medical and food-contact applications, LSR offers unparalleled biocompatibility that meets the most stringent global regulatory standards:
Specialty pharmaceutical-grade LSR formulations further reduce extractable and leachable (E&L) levels to <0.1 μg/mL, meeting USP <661> and <1663> requirements for single-use bioprocessing components such as tubing, stopper seals, and bioreactor gaskets.
LSR’s low viscosity (1,000–100,000 cP at room temperature) enables unique processing capabilities that are not feasible with solid rubber materials. Modern processing techniques optimize material yield, part precision, and functional integration, addressing historical limitations of LSR manufacturing such as flash and long cure cycles.
LIM is the dominant manufacturing method for high-volume LSR parts, leveraging a two-part (A and B) material system that is mixed in a 1:1 ratio immediately before injection into a heated mold. The process offers significant advantages over compression molding, including 50–70% faster cycle times, 95%+ material utilization, and the ability to mold parts with wall thicknesses as low as 0.1 mm. Key process parameters and their recommended ranges are listed in Table 2.
Advanced LIM systems integrate in-line viscosity monitoring and closed-loop ratio control to reduce part defect rates to <0.1%, a critical improvement for medical device manufacturing where part consistency is non-negotiable. Cold-runner mold systems further eliminate waste by keeping the material in the runner channels cool and uncured, reducing post-processing trimming requirements by 90% compared to hot-runner designs.
One of LSR’s most valuable processing advantages is its ability to bond to a wide range of engineering substrates during molding, eliminating the need for secondary assembly steps. LSR can be overmolded directly onto polycarbonate (PC), polyamide (PA), polyethylene terephthalate (PET), and aluminum alloys, provided the substrate is pre-treated with a primer or plasma activation to improve interfacial adhesion. Typical bond strengths for overmolded assemblies range from 3–8 MPa, exceeding the tensile strength of many adhesive bonds.
To address LSR’s naturally low surface energy (22–24 mN/m), which limits its printability and ability to bond to pressure-sensitive adhesives (PSA), several surface modification techniques are commercially available:
These modification techniques expand LSR’s application scope to use cases that demand surface functionality, such as wearable device sensors that require skin-safe adhesive bonding and medical components that need anti-fouling coatings to prevent protein adsorption.
LSR硅橡胶’s unique combination of properties has driven widespread adoption across diverse sectors, with each industry leveraging specific performance attributes to solve engineering challenges. This section analyzes high-growth application areas, with a focus on design requirements and performance validation criteria.
The medical sector accounts for 28% of global LSR consumption, driven by its biocompatibility, sterilization resistance, and design flexibility. Key medical applications include:
For wearable medical devices such as continuous glucose monitors (CGMs) and ECG patches, LSR’s softness (10–30 Shore A) and skin biocompatibility reduce irritation during 7–14 day wear periods, while its low moisture absorption (<0.1% by weight after 24 hours of water immersion) prevents skin maceration under the device.
The transition to electric vehicles (EVs) has accelerated LSR adoption in the automotive sector, which now accounts for 22% of global LSR demand. Key automotive use cases include:
Automotive-grade LSR meets ISO 16750 requirements for environmental resistance, with <10% weight gain after 1,000 hours of exposure to automotive fluids, and passes UL 94 V-0 flammability standards for under-hood and battery pack applications.
LSR’s dielectric strength, water resistance, and aesthetic flexibility make it a preferred material for consumer electronics, while its mechanical resilience drives adoption in industrial sealing and fluid handling systems.
As demand for high-performance elastomers grows, material scientists and manufacturers are developing next-generation LSR硅橡胶 formulations and processing techniques to expand its application scope further.
The fastest-growing segment of the LSR market is functional grades tailored to niche application requirements:
Historically, LSR’s thermoset structure has made it difficult to recycle, but recent advances in material design and processing are addressing this gap:
LSR硅橡胶 is a versatile high-performance elastomer that offers a unique combination of thermal stability, biocompatibility, mechanical resilience, and processing flexibility unmatched by conventional organic rubbers and thermoplastics. Its core properties, including a wide service temperature range, low compression set, and regulatory compliance for medical and food contact, make it suitable for critical applications across healthcare, automotive, consumer electronics, and industrial sectors. Advanced processing techniques such as precision LIM, multi-material overmolding, and surface modification have further expanded its use cases, enabling the production of complex, integrated parts with high dimensional accuracy and low waste.
As material innovation continues, functional LSR grades (conductive, self-healing, foamed) and sustainable recycling solutions will drive further adoption, particularly in high-growth areas such as EV manufacturing, wearable medical devices, and 5G electronics. For engineering and product development teams, selecting the right LSR grade requires careful consideration of application-specific requirements for mechanical performance, chemical exposure, regulatory compliance, and processing feasibility. With ongoing advances in formulation and circular economy practices, LSR will remain a foundational material for high-tech product development for decades to come.